Chromatography is a well known method of separating a sample composed of one or more chemical constituents to aid in the determination of the identity of the chemical constituents and quantitatively determine the concentration of the chemical constituents. FIG. 1 shows a typical chromatography apparatus 10 in accordance with the prior art. The chromatography apparatus 10 includes a mobile phase supply 12 holding a mobile phase or carrier fluid 13 that is typically, a solvent in liquid chromatography and an inert gas in gas chromatography. The mobile phase supply 12 is coupled to a pump 14 via a fluid line 16. The pump 14 is operable to pump the mobile phase 13 from the mobile phase supply 12 to a mixture injection port 20 via fluid line 18. A sample supply 21, holding a sample 22 to be analyzed, is also coupled to the mixture injection port 20 through a fluid line 24. In operation, the pump 14 pumps the mobile phase 13, which sweeps the sample 22 through the mixture injection port 20 and a feed line 26, and into a packed column 28 having a stationary phase support 38 (FIG. 2).
The packed column 28 may be surrounded by a heating element 34 that is operable to heat the packed column 28 to a desired temperature. A detector 32 is coupled to the packed column 28 via a fluid line 30 to receive the different chemical constituents of the sample 22 separated by the packed column 28 and is configured to indicate the presence and/or concentration of chemical constituents of the sample 22 being analyzed by measuring a property that is related to the concentration and/or characteristic of the chemical constituents.
As shown in FIG. 2, the packed column 28 includes a tubular housing 36 formed from a glass, metal, or polymer that encloses and supports the stationary phase support 38. Some of the more common materials that the stationary phase support 38 can be made from is diamond powder, silica powder, and graphitic powder that define a generally granular porous structure through which the mixture of the mobile phase 13 and the sample 22 can pass through. The powdered materials may serve as a stationary phase if the chemical constituents of the sample 22 have different affinities to the powdered materials. However, sometimes the powdered materials may be coated with a liquid, an adsorbent, or chemical species that functions as the stationary phase and the powdered material merely serves as a support structure. The housing 36 has a liner 40 coating the interior thereof to help reduce chemical activity between the sample 22 and the housing 36. The liner 40 can be formed from an inert material such as polytetrafluoroethylene (“PTFE”) or a metallic material such as stainless steel or nickel.
With reference to FIGS. 1 and 2, in operation, a mixture 27 of the mobile phase 13 and the sample 22 are introduced into the packed column 28 through the mixture injection port 20. As the mixture 27 passes through the stationary phase support 38 of the packed column 28, a flow 42 of different chemical constituents 42a and 42b emerge from the packed column 28 at different times. As best shown in FIG. 2, the constituent 42a with the least affinity for the stationary phase support 38 or a stationary phase disposed therein emerges first, while the constituent 42b with the greatest affinity for the stationary phase support 38 or a stationary phase disposed therein emerges at a later time. The flow 42 of the constituents 42a and 42b are collected as they emerge from the packed column 28 and the detector 32 analyzes the flow 42 by measuring a property that is related to the concentration and characteristic of the chemical constituents 42a and 42b such as the refractive index or ultra-violet absorbance in order to identify the chemical composition and concentration of the constituents 42a and 42b. The signal from the detector 32 can be displayed on a computer (not shown) or another display device.
One problem with the prior art chromatography apparatus 10 is that a highly basic or acidic mobile phase 13 and/or sample 22 can chemically attack and degrade the liner 40 and/or the stationary phase support 38. This degradation can be further exacerbated at high temperatures. For example, a PTFE liner 40 is limited to temperatures below 200° C. Degradation of the liner 40 and the stationary phase support 38 can introduce error into any subsequent chemical analysis performed by the detector 32 on the constituents 42a and 42b. 
Therefore, there is a still a need for a separation device, and a stationary phase and/or support structure that can be used at high temperatures and/or with a wide range of highly aggressive chemicals.